Mobile wireless communications subscriber devices and cellular subscriber communications networks are increasingly providing and supporting technologies that enable location determination of the subscriber devices, for example, for compliance with the emergency location services, like E-911 mandated by the Federal Communications Commission, and increasingly for location-based e-commerce services and applications.
Many communications networks however do not support location technologies, and some networks support one technology but not others. Thus many subscriber devices may perform location measurements or computations that are not required by a particular network, resulting in unnecessary power consumption and less than optimal resource allocation.
Some satellite positioning system (SPS) enabled subscriber devices to compute position at the subscriber device. In some instances the subscriber device computes location autonomously. In communications networks, however, many subscriber devices request the location information from the network or require assistance information from the network for accurate location computation. This information may include, for example, precise time, frequency calibration, and satellite positioning system navigation information, etc.
As mobile stations roam from base station to base station and network to network, some networks will have the capability to respond to the location request. However other networks will not have this capability. The mobile station will continue to request location information even though the network can not send the pertinent information. Consequently the mobile station will incur undesired current drain and network resources will be inefficiently utilized.
In the exemplary GSM system, not all systems in place have mobile originated location request (MO-LR) capability. If the subscriber device makes a MO-LR and the network does not support MO-LR, the device will not receive the requested information or will receive an error message. Some devices then repeatedly request location information even though the network can not respond. Multiple requests to a network for the information wastes not only the mobile and network resources but also results in unwanted current drain on the mobile station.
Although some networks will be able to respond to the location information request, the mobile station may not support the form or type of data provided in response to a request as there are a plurality of supported formats and protocols. For example, one protocol defines “shape” data which is determined by how the location of the mobile station is calculated and then further what type of data is sent to the device. However, if the network does not provide support for the shape that is supported by the mobile station, the mobile station will not be able to use the data to determine the mobile station location. Subsequent requests by the mobile station uses network resources and increased current drain at the mobile station.
The various aspects, features and advantages of the present inventions will become more fully apparent to those having ordinary skill in the art upon careful consideration of the following Detailed Description of the Invention with the accompanying drawings described below.